1. Field of the Invention
This invention relates to pulleys, gears and other rotational members and the means for attaching them to their shafts so that they have the ability to move and align themselves when the driving force that is applied to the rotational member's perimeter is not always in the same direction. For example, when this force is not always directed exactly perpendicular to the shaft's rotational axis.
2. Description of the Related Art
In assorted machines or mechanical drive systems where cables are operated over pulleys, sheaves or other rotational members, it has always been difficult to align and mount these members so as to insure a continuing, perfect alignment between the cable and the rotating member. Even slight misalignment can yield cable chafing on the rotational member and result in undue wear at the affected contact points of such systems and the creation of undesirable noise in the use of such systems.
This situation often results in the system having to be shut down while realignment is attempted or replacement parts are installed. Additionally, it can increase the danger of cable failure which could have dire consequences for those that work in the vicinity of such systems or depend on the reliability of their operation.
In addition to such maintenance and safety considerations, these systems also suffer from the limitation of having very little flexibility is the manner in which such systems can be designed. Because of the need for the precise alignment of the components of such systems (i.e., a pulley, gear, etc. must be mounted at right angles to the shaft on which it is mounted, and the plane defined by a belt, chain, cable, etc. running on the perimeter of such a member must coincide with the plane of the member), the positioning of these elements can often require more space for mounting than is ideal, especially if one is trying to minimize the space consumed by such systems.
Various alignable pulleys and the means for mounting standard pulleys so as to make them self-aligning have been suggested. For example, see U.S. Pat. Nos. 2,279,887, 2,421,685 and 6,811,506.
Despite this prior art, further improvements appear to be needed as there still exist many type of mechanical equipment (e.g., power mowers) that utilize such systems and which experience greater than acceptable amounts of downtime to maintain and repair such systems.
3. Objects and Advantages
There has been summarized above, rather broadly, the prior art that is related to the present invention in order that the context of the present invention may be better understood and appreciated. In this regard, it is instructive to also consider the objects and advantages of the present invention.
It is an object of the present invention to provide an improved self-aligning pulley or sheave assembly.
It is an object of the present invention to provide a means for mounting a pulley or sheave on its shaft that will enable such rotational members to continually realign themselves as necessary to compensate for changes in the direction of the forces that are being applied to their perimeters.
It is also an object of the present invention to provide an improved self-aligning pulley or sheave assembly that will allow for the dynamic positioning of such a member on its drive shaft.
It is an object of the present invention to provide an improved self-aligning pulley or sheave that will allow for such a member to reposition itself on its drive shaft so as to always stay in proper alignment.
It is yet another object of the present invention to provide an improved self-aligning pulley or sheave assembly that is ideally suited for use in both manual and power mower applications.
It is a further object of the present invention to provide a means for significantly reducing the downtime necessary to maintain and repair mechanical equipment that utilizes cable and pulley/sheave systems.
It is also an object of the present invention to provide an alignable pulley or sheave that is reliable and simple and inexpensive to manufacture and maintain.
These and other objects and advantages of the present invention will become readily apparent as the invention is better understood by reference to the accompanying summary, drawings and the detailed description that follows.